
MAX860/MAX861
50mA, Frequency-Selectable,
Switched-Capacitor Voltage Converters
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(Typical Operating Circuit (Inverter), V
DD
= +5V,
–
S
—
H
—
D
—
N
–
= V
DD
, FC = LV = GND, C1 = C2 = 10µF (Note 2), T
A
= T
MIN
to T
MAX
, unless
otherwise noted. Typical values are at T
A
= +25°C.)
Note 2: C1 and C2 are low-ESR (<0.2Ω) aluminum electrolytics. Capacitor ESR adds to the circuit’s output resistance. Using
capacitors with higher ESR may reduce output voltage and efficiency.
Note 3: Specified output resistance includes the effect of the 0.2Ω ESR of the test circuit’s capacitors.
Note 4: The switches are driven directly at the oscillator frequency, without any division.
Note 5: At lowest frequencies, using 10µF capacitors gives worse efficiency figures than using the recommended capacitor
values in Table 3, due to larger 1 ⁄ (f
s
x C1) term in R
OUT
.
–
S
—
H
—
D
—
N
–
< 0.3V
MAX860
LV = GND
No load
MAX860/MAX861, FC = V
DD
,
I
L
= 50mA to GND, C1 = C2 = 68µF
MAX860,
FC = V
DD
MAX861,
FC = V
DD
MAX861
FC < 4V
CONDITIONS
µA
10
Shutdown Supply Current
1
V
0.3V
IL
–
S
—
H
—
D
—
N
–
Threshold
1.2V
IH
%99 99.9Voltage-Conversion Efficiency
%
87
Power Efficiency (Note 5)
88 92
93 96
80 130
30 50
36
90 93
93 96
813
60 100
kHz
160 250
f
S
Switching Frequency
(Note 4)
µA-2 -4I
FC
FC Current (from V
DD
)
UNITSMIN TYP MAXSYMBOLPARAMETER
No load, V
OUT
= -4V µs500Time to Exit Shutdown
FC = V
DD
FC = GND
FC = OUT
FC = V
DD
FC = GND
FC = OUT
R
L
= 2kΩ from V
DD
to OUT
R
L
= 1kΩ from OUT
to GND
R
L
= 2kΩ from V
DD
to OUT
R
L
= 1kΩ from OUT
to GND
MAX86_I/E
MAX86_M
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